Frozen soft-serve confections such as ice creams and yogurts have gained wide popularity among the consumers. Such soft serve products are conventionally made on-site at retail outlets. Typically, a liquid mix is poured into a mixer and dispensing unit wherein the mix is combined with air under proper agitation at appropriate temperatures. This produces a soft-serve product which is maintained within the unit at the dispensing temperature until dispensed.
On site production of soft-serve products works well but has several drawbacks. The machinery requires extensive cleaning which, if not done properly, leads to bacterial contamination. The machinery, which is fairly complex, is expensive and subject to frequent breakdown. The production of small quantities of product at numerous sites by different individuals leads to inconsistency in quality control and hence, product quality.
It has been suggested that the soft serve product be formulated and produced in final dispensing form at a central facility, and then hard frozen for storage and shipping. "Hard frozen" refers to a temperature below the dispensing temperature and typically below or at about 0.degree. F. Once a hard frozen product is received at the retail site, it is thawed or tempered to and maintained at the desired dispensing temperature, and then dispensed. Such a process obviates a need for a combined mixing and dispensing unit and allows the use of a simpler dispensing apparatus at the retail site.
PCT Application No. WO 90/05697 discloses an apparatus for dispensing frozen soft serve confections from a collapsible bag. The bag is mounted vertically within a dispensing cabinet and soft serve product is dispensed at the top of the bag through a valve. The soft serve product is urged out of the bag by a movable piston.